The Chemical Entities of Biological Interest (ChEBI) ontology is downloaded weekly from EMBL-EBI at http://www.ebi.ac.uk/chebi/. The data is made available under the Creative Commons License (CC BY 3.0, http://creativecommons.org/licenses/by/3.0/). For more information see: Degtyarenko et al. (2008) ChEBI: a database and ontology for chemical entities of biological interest. Nucleic Acids Res. 36, D344–D350.
An amino acid betaine that is ergothioneine in which the hydrogen attached to the sulfur is replaced by a methyl group. It has been isolated from the deepwater (500-1,600 m) marine sponge Macandrewia azorica.